The preparation of ultrastable Al3+ doped CeO2 supported Au catalysts: Strong metal-support interaction for superior catalytic activity towards CO oxidation

Abstract

The classical strong metal-support interaction (SMSI) plays a key role in improving thermal stability for supported Au catalysts. However, it always decreases the catalytic activity because of the encapsulation of Au species by support. Herein, we demonstrate that Al3+ is a functional additive which could effectively improve both catalytic activity and sintering resistant property for H2 pretreated Al3+ doped CeO2 supported Au (AuCeAl) catalyst at high temperature. The physical characterization and in-situ DRIFTS results provide insight that more oxygen vacancies generated by Al3+ doping could be as preferential adsorption sites for CO molecules when the encapsulation of Au species occurred, which is certificated by an accelerated formation of bicarbonate species. In the meantime, smaller Au nanoparticles with higher dispersion (2.8 nm, 85.63%) is achieved in AuCeAl catalysts, compared with that in CeO2 supported Au (AuCe) catalysts (5.1 nm, 36.17%). Additionally, the as-prepared AuCeAl catalysts also have superior catalytic performance even after calcination at 800 °C in air.